General Information
When you are defining a problem in the power train system, the following procedure should be followed:
- Prepare the machine for service.
- Perform the visual checks.
- If the problem has not been identified, perform the operation checks.
- If the problem is not fully understood, perform the instrument tests.
- When the problem is defined, go to Troubleshooting. Troubleshooting information can be found in Troubleshooting, RENR9831. This manual lists the probable causes of a known problem. As there may be more than one cause for a problem, the Troubleshooting manual may suggest specific inspections or instrument tests be done. The inspections and the tests help identify the most probable cause of a problem. The list cannot give all possible problems and corrections.
During a diagnosis of the power train system, remember that correct oil flow and pressure are necessary for correct operation. The output of the power train oil pump increases with an increase in engine speed and decreases when engine speed is decreased. Oil pressure is caused by resistance to the flow of oil.
Locations of the pressure taps and of the components are given in the Systems Operation portion of this manual.
Note: Caterpillar Monitoring System accesses many values that are useful in troubleshooting the power train system. When the situation is appropriate, use Caterpillar Monitoring System in order to find a pressure or determine a system problem.
Warnings
Refer to the following warnings and notices for all inspections and tests of the power train.
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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the power train. |
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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
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Personal injury or death can result from not engaging the parking brake. Transmission engagement alone will not prevent machine from rolling when the engine is stopped. |
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Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake. |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
Procedure
Before you troubleshoot, complete the following procedure.
- Move the machine to a smooth, horizontal location that is away from operating machines and away from personnel.
Note: Permit only one operator on the machine. Keep all other personnel away from the machine or in the operator's sight.
- Place the steering control lever in the NEUTRAL position.
- Engage the parking brake.
- Fully retract the counterweight.
- Stop the engine.
- Move the control levers through the full range of travel. This will relieve any pressure that may be present in the implement hydraulic system.
- Make sure that the pressure in the entire hydraulic system has been released.
ReferenceRefer to Troubleshooting, RENR9831 for additional guidance for preparing the machine for testing.
Note: Caterpillar Monitoring System can be used to check certain pressures and temperatures.
The following temperatures can be checked by using Caterpillar Monitoring System for the power train system:
- Oil temperature for the torque converter
- Oil temperature for the oil in the sump for the transmission